Children can understand basic words like \"apple\" and \"arm\" aged just six months – almost twice as early as previously thought, researchers claim. Although most children do not speak meaningful words until their first birthday, the findings suggest they can in some cases understand what an adult is referring to much earlier, the Daily Telegraph reported today. It contradicts the consensus that while babies can understand elements of sounds in their native language between six and nine months, they do not fully comprehend the meaning of speech until close to their first birthday. In a study published in the Proceedings of the National Academy of Sciences journal, 33 infants aged six to nine months were tested on their understanding of common nouns, such as foods or body parts, alongside 50 children aged 10 to 20 months. The children were shown a screen showing two images, such as an apple and an arm, and asked by their mother where one of the objects was. Researchers tracked the infants\' eye movements and found that 26 of the 33 six to nine-month-olds tended to glance at the correct image with a frequency that was unlikely to be down to chance. Results from the same test on older children showed that there was no significant improvement between the ages of six and 14 months, when levels of understanding improved rapidly. In a second test the children were asked to locate an object in the context of a scene rather than in isolation, such as a banana on a dinner table containing other types of food. Results showed that children could locate at least some of the tested words in the scene. Dr Daniel Swingley, one of the researchers from the University of Pennsylvania, said: \"I think this study presents a great message to parents: You can talk to your babies and they\'re going to understand a bit of what you\'re saying. \"They\'re not going to give us back witty repartee, but they understand some of it. And the more they know, the more they can build on what they know.\"